907 resultados para SENSORLESS DRIVES


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Numerical experiments are described that pertain to the climate of a coupled atmosphere–ocean–ice system in the absence of land, driven by modern-day orbital and CO2 forcing. Millennial time-scale simulations yield a mean state in which ice caps reach down to 55° of latitude and both the atmosphere and ocean comprise eastward- and westward-flowing zonal jets, whose structure is set by their respective baroclinic instabilities. Despite the zonality of the ocean, it is remarkably efficient at transporting heat meridionally through the agency of Ekman transport and eddy-driven subduction. Indeed the partition of heat transport between the atmosphere and ocean is much the same as the present climate, with the ocean dominating in the Tropics and the atmosphere in the mid–high latitudes. Variability of the system is dominated by the coupling of annular modes in the atmosphere and ocean. Stochastic variability inherent to the atmospheric jets drives variability in the ocean. Zonal flows in the ocean exhibit decadal variability, which, remarkably, feeds back to the atmosphere, coloring the spectrum of annular variability. A simple stochastic model can capture the essence of the process. Finally, it is briefly reviewed how the aquaplanet can provide information about the processes that set the partition of heat transport and the climate of Earth.

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Flavonoids reduce cardiovascular disease risk through anti-inflammatory, anti-coagulant and anti-platelet actions. One key flavonoid inhibitory mechanism is blocking kinase activity that drives these processes. Flavonoids attenuate activities of kinases including phosphoinositide-3-kinase (PI3K), Fyn, Lyn, Src, Syk, PKC, PIM1/2, ERK, JNK, and PKA. X-ray crystallographic analyses of kinase-flavonoid complexes show that flavonoid ring systems and their hydroxyl substitutions are important structural features for their binding to kinases. A clearer understanding of structural interactions of flavonoids with kinases is necessary to allow construction of more potent and selective counterparts. We examined flavonoid (quercetin, apigenin and catechin) interactions with Src-family kinases (Lyn, Fyn and Hck) applying the Sybyl docking algorithm and GRID. A homology model (Lyn) was used in our analyses to demonstrate that high quality predicted kinase structures are suitable for flavonoid computational studies. Our docking results revealed potential hydrogen bond contacts between flavonoid hydroxyls and kinase catalytic site residues. Identification of plausible contacts indicated that quercetin formed the most energetically stable interactions, apigenin lacked hydroxyl groups necessary for important contacts, and the non-planar structure of catechin could not support predicted hydrogen bonding patterns. GRID analysis using a hydroxyl functional group supported docking results. Based on these findings, we predicted that quercetin would inhibit activities of Src-family kinases with greater potency than apigenin and catechin. We validated this prediction using in vitro kinase assays. We conclude that our study can be used as a basis to construct virtual flavonoid interaction libraries to guide drug discovery using these compounds as molecular templates.

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The North Atlantic Ocean subpolar gyre (NA SPG) is an important region for initialising decadal climate forecasts. Climate model simulations and palaeo climate reconstructions have indicated that this region could also exhibit large, internally generated variability on decadal timescales. Understanding these modes of variability, their consistency across models, and the conditions in which they exist, is clearly important for improving the skill of decadal predictions — particularly when these predictions are made with the same underlying climate models. Here we describe and analyse a mode of internal variability in the NA SPG in a state-of-the-art, high resolution, coupled climate model. This mode has a period of 17 years and explains 15–30% of the annual variance in related ocean indices. It arises due to the advection of heat content anomalies around the NA SPG. Anomalous circulation drives the variability in the southern half of the NA SPG, whilst mean circulation and anomalous temperatures are important in the northern half. A negative feedback between Labrador Sea temperatures/densities and those in the North Atlantic Current is identified, which allows for the phase reversal. The atmosphere is found to act as a positive feedback on to this mode via the North Atlantic Oscillation which itself exhibits a spectral peak at 17 years. Decadal ocean density changes associated with this mode are driven by variations in temperature, rather than salinity — a point which models often disagree on and which we suggest may affect the veracity of the underlying assumptions of anomaly-assimilating decadal prediction methodologies.

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The basic premise of this article is that typefaces reflect, and respond to, the conditions of making and using documents; and that demand for evolving document genres drives the development of new typefaces. The article describes how the combination of a narrow range for functionally acceptable letters and paragraphs, and a wide range of possibilities to express these arrangements, offers a revealing tool for examining changes in the perceptions of professionals in visual communication. Beyond technical issues, the choices of document makers allow insights into wider trends such as urbanisation, demographic changes, education standards, and wider issues of visual literacy.

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This paper argues that offshoring indices often measure something different than what we think they are. Using data from input-output tables of 21 European countries from 1995 to 2006 we decompose an offshoring index, distinguishing between a domestic (structural change) and an international component (imported inputs ratio). Regarding offshoring of business services, a large share of the index variation is driven by the domestic component. This is even more pronounced for overall service offshoring. In the case of material offshoring, by contrast, the international component drives the main variation of the indices. Our results therefore show that, regarding (business) services, the typical calculation of offshoring indices tends to over estimate the role of the imported inputs component, neglecting the role played by structural changes in the economy.

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The Madden-Julian oscillation (MJO) is a convectively coupled 30-70 day (intraseasonal) tropical atmospheric mode that drives variations in global weather, but which is poorly simulated in most atmospheric general circulation models. Over the past two decades, field campaigns and modeling experiments have suggested that tropical atmosphere-ocean interactions may sustain or amplify the pattern of enhanced and suppressed atmospheric convection that defines the MJO, and encourage its eastward propagation through the Indian and Pacific Oceans. New observations collected during the past decade have advanced our understand of the ocean response to atmospheric MJO forcing and the resulting intraseasonal sea surface temperature (SST) fluctuations. Numerous modeling studies have revealed a considerable impact of the mean state on MJO ocean-atmosphere coupled processes, as well as the importance of resolving the diurnal cycle of atmosphere--upper-ocean interactions. New diagnostic methods provide insight to atmospheric variability and physical processes associated with the MJO, but offer limited insight on the role of ocean feedbacks. Consequently, uncertainty remains concerning the role of the ocean in MJO theory. Our understanding of how atmosphere-ocean coupled processes affect the MJO can be improved by collecting observations in poorly sampled regions of MJO activity, assessing oceanic and atmospheric drivers of surface fluxes, improving the representation of upper-ocean mixing in coupled-model simulations, designing model experiments that minimize mean-state differences, and developing diagnostic tools to evaluate the nature and role of coupled ocean-atmosphere processes over the MJO cycle.

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Actin polymerization drives multiple cell processes involving movement and shape change. SCAR/WAVE proteins connect signaling to actin polymerization through the activation of the Arp2/3 complex. SCAR/WAVE is normally found in a complex with four other proteins: PIR121, Nap1, Abi2,and HSPC300 (Figure S1A available online) [1-3]. However,there is no consensus as to whether the complex functions as an unchanging unit or if it alters its composition in response to stimulation, as originally proposed by Edenet al. [1]. It also is unclear whether complex members exclusively regulate SCAR/WAVEs or if they have additional targets [4-6]. Here, we analyze the roles of the unique Dictyostelium Abi. We find that abiA null mutants show less severe defects in motility than do scar null cells, indicating--unexpectedly--that SCAR retains partial activity in the absence of Abi. Furthermore, abiA null mutants have a serious defect in cytokinesis, which is not seen in other SCAR complex mutants and is seen only when SCAR itself is present. Detailed examination reveals that normal cytokinesis requires SCAR activity, apparently regulated through multiple pathways.

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Small and medium sized enterprises (SMEs) play an important role in the European economy. A critical challenge faced by SME leaders, as a consequence of the continuing digital technology revolution, is how to optimally align business strategy with digital technology to fully leverage the potential offered by these technologies in pursuit of longevity and growth. There is a paucity of empirical research examining how e-leadership in SMEs drives successful alignment between business strategy and digital technology fostering longevity and growth. To address this gap, in this paper we develop an empirically derived e-leadership model. Initially we develop a theoretical model of e-leadership drawing on strategic alignment theory. This provides a theoretical foundation on how SMEs can harness digital technology in support of their business strategy enabling sustainable growth. An in-depth empirical study was undertaken interviewing 42 successful European SME leaders to validate, advance and substantiate our theoretically driven model. The outcome of the two stage process – inductive development of a theoretically driven e-leadership model and deductive advancement to develop a complete model through in-depth interviews with successful European SME leaders – is an e-leadership model with specific constructs fostering effective strategic alignment. The resulting diagnostic model enables SME decision makers to exercise effective e-leadership by creating productive alignment between business strategy and digital technology improving longevity and growth prospects.

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Aims. Orthoptists are familiar with AC/A ratios and the concept that accommodation drives convergence, but the reverse relationship, that of the accommodation associated with convergence, is rarely considered. Methods. This article reviews published evidence from our laboratory which has investigated the drives to both vergence and accommodation. All studies involved a method by which accommodation and vergence were measured concurrently and objectively to a range of visual stimuli which manipulate blur, disparity and proximal/looming cues in different combinations. Results Results are summarised for both typical and atypical participants, and over development between birth and adulthood. Conclusions For the majority of typical children and adults, as well as patients with most heterophorias and intermittent exotropia, disparity is the main cue to both vergence and accommodation. Thus the convergence→accommodation relationship is more influential than that of accommodative vergence. Differences in “style” of near cue use may be a more useful way to think about responses to stimuli moving in depth, and their consequences for orthoptic patients, than either AC/A or CA/C ratios. The implications of a strong role for vergence accommodation in orthoptic practice are considered.

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Classical nova remnants are important scenarios for improving the photoionization modeling. This work describes the pseudo-three-dimensional code RAINY3D, which drives the photoionization code Cloudy as a subroutine. Photoionization simulations of old nova remnants are also presented and discussed. In these simulations we analyze the effect of condensation in the remnant spectra. The condensed mass fraction affects the Balmer lines by a factor of greater than 4 when compared with homogeneous models, and this directly impacts the shell mass determination. The He II 4686/H beta ratio decreases by a factor of 10 in clumpy shells. These lines are also affected by the clump size and density distributions. The behavior of the strongest nebular line observed in nova remnants is also analyzed for heterogeneous shells. The gas diagnoses in novae ejecta are thought to be more accurate during the nebular phase, but we have determined that at this phase the matter distribution can strongly affect the derived shell physical properties and chemical abundances.

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Component-based software engineering has recently emerged as a promising solution to the development of system-level software. Unfortunately, current approaches are limited to specific platforms and domains. This lack of generality is particularly problematic as it prevents knowledge sharing and generally drives development costs up. In the past, we have developed a generic approach to component-based software engineering for system-level software called OpenCom. In this paper, we present OpenComL an instantiation of OpenCom to Linux environments and show how it can be profiled to meet a range of system-level software in Linux environments. For this, we demonstrate its application to constructing a programmable router platform and a middleware for parallel environments.

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We have studied by numerical simulations the relaxation of the stochastic seven-state Potts model after a quench from a high temperature down to a temperature below the first-order transition. For quench temperatures just below the transition temperature the phase ordering occurs by simple coarsening under the action of surface tension. For sufficient low temperatures however the straightening of the interface between domains drives the system toward a metastable disordered state, identified as a glassy state. Escaping from this state occurs, if the quench temperature is nonzero, by a thermal activated dynamics that eventually drives the system toward the equilibrium state. (C) 2009 Elsevier B.V. All rights reserved.

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Energy efficiency and renewable energy use are two main priorities leading to industrial sustainability nowadays according to European Steel Technology Platform (ESTP). Modernization efforts can be done by industries to improve energy consumptions of the production lines. These days, steel making industrial applications are energy and emission intensive. It was estimated that over the past years, energy consumption and corresponding CO2 generation has increased steadily reaching approximately 338.15 parts per million in august 2010 [1]. These kinds of facts and statistics have introduced a lot of room for improvement in energy efficiency for industrial applications through modernization and use of renewable energy sources such as solar Photovoltaic Systems (PV).The purpose of this thesis work is to make a preliminary design and simulation of the solar photovoltaic system which would attempt to cover the energy demand of the initial part of the pickling line hydraulic system at the SSAB steel plant. For this purpose, the energy consumptions of this hydraulic system would be studied and evaluated and a general analysis of the hydraulic and control components performance would be done which would yield a proper set of guidelines contributing towards future energy savings. The results of the energy efficiency analysis showed that the initial part of the pickling line hydraulic system worked with a low efficiency of 3.3%. Results of general analysis showed that hydraulic accumulators of 650 liter size should be used by the initial part pickling line system in combination with a one pump delivery of 100 l/min. Based on this, one PV system can deliver energy to an AC motor-pump set covering 17.6% of total energy and another PV system can supply a DC hydraulic pump substituting 26.7% of the demand. The first system used 290 m2 area of the roof and was sized as 40 kWp, the second used 109 m2 and was sized as 15.2 kWp. It was concluded that the reason for the low efficiency was the oversized design of the system. Incremental modernization efforts could help to improve the hydraulic system energy efficiency and make the design of the solar photovoltaic system realistically possible. Two types of PV systems where analyzed in the thesis work. A method was found calculating the load simulation sequence based on the energy efficiency studies to help in the PV system simulations. Hydraulic accumulators integrated into the pickling line worked as energy storage when being charged by the PV system as well.

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Solid State Diskar (SSD) är relativt nya och mycket om dem är okänt. Detta examensarbete fokuserar på att läsa forensiskt viktig information från både lagringsutrymmet och reservutrymmet. Detta har försökts genom att ett program har byggts i C++, detta program använder ATA kommandon för att läsa information från disken. Även om programmet aldrig blev färdigt kunde det skicka och ta emot data från en SSD, dock inte reservutrymmet vilket var fokus i detta examensarbete.

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Meanings of overweight In societal discourses overweight is defined as a growing individual and a social problem leading to sickness and disability, mental distress, increased use of health care and reduced economic productivity. A strong normative pressure is directed at the overweight but relatively few succeed in reducing their weight. Therefore, the overweight need to manage a double stigma; the overweight body per se and their inability to conform to norms about bodyweight. This article investigates how individuals present their overweight to their social environment. Empirical data was collected as part of an evaluation study of a keep-fit project directed at home-care staff. Qualitative interviews were conducted with 49 participants and 30 of them had either tried or were trying to reduce their weight. The analysis shows that the informants presented a divided self consisting of a biological body, with its own drives, and a mind that is aware of the body and its social meanings. They portrayed their lives as a battle between these two sides. Their presentations of the divided self can be analysed as a defence of their social selves. The overweight can account for the kilos by blaming the biological drives, which leaves the core of themselves – their minds – unblemished. They can express an intention to loose weight and thereby conform to norms about bodyweight. When they fail to loose weight, the responsibility can be attributed to the unruly body.